[4] In the Fall he entered Stanford University, and in his senior year, 1956, he played in the final of the NCAA Singles Championship, losing to Alex Olmedo of U.S.C.

Following military service, Frost played the international tennis circuit between 1958 and 1963, competing in six Wimbledon Championships and getting out to the 4th round in 1960, before losing to Nicola Pietrangeli.

[6] He won the Irish[7] and Wiesbaden[8] (including the mixed doubles with Maria Bueno) and was in the finals of the South African,[9] the Canadian,[10] the Norwegian[11] and the Good Neighbor.

[12] During the course of his career he had singles wins in major grass court tournaments over all-time greats Rod Laver,[13] Roy Emerson[14] and Vic Seixas[15] and over numerous international Davis-Cup mainstays on various surfaces: Luis Ayala,[16] Thomaz Koch,[17] Mario Llamas,[18] Antonio Palafox,[19] Giuseppe Merlo,[20] Istvan Gulyas,[21] Bob Mark,[22] Frew McMillan,[23] Christian Kuhnke,[24] Bob Hewitt,[25] Gordon Forbes,[26] Warren Woodcock,[27] Billy Knight,[28] Ron Holmberg,[29] Dennis Ralston,[30] Barry Mackay,[31]"Jack Douglas"[32] and Tom Brown.

Simultaneously, through a series of National Defense Foreign Language grants, he was able to become proficient in Arabic and Swahili and eventually was awarded a Fulbright Fellowship to cover a year abroad, some four months of it to be spent in Khartoum (Sudan).